Silver halide photosensitive element containing an antifogging combination of a nitrated heterocyclic compound and a polymeric stabilizer

ABSTRACT

ANTI-FOGGING AGENTS FOR SILVER HALIDE PHOTOGRAPHIC EMULSIONS CONSISTING OF A COMBINATION OF (A) AN NITRATED BENZIMIDAZOLE, INDAZOLE OR BENZOTRIAZOLE COMPOUND REPRESENTED BY THE GENERAL FORMULA 1,2-(-X=Y-NH-),(O2N-)BENZENE WHEREIN X AND Y INDIVIDDUALLY REPRESENT N OR CR, WHEREIN R REPRESENTS A HYDROGEN ATOM OR ALKYL GROUP CONTAINING 1 TO 4 CARBON ATOMS, AND (B) AT LEAST ONE MEMBER SELECTED FROM POLYMERS CONTAINING GREATER THAN 50 MOL PERCENT OF RECURRING UNITS REPRESENTED BY THE GENERAL FORMULA -(CH2-CH(-N(-R1)-CO-R2))WHEREIN R1 AND R2 INDIVIDUALLY REPRESENT A HYDROGEN ATOM OR AN ALKYL GROUP CONTAINING 1 TO 4 CARBON ATOMS OR FORM, WHEN TAKEN TOGETHER WITH THE NITROGEN AND CARBON ATOMS TO WHICH THEY ARE ATTACHED, A 5- OR 7-MEMBERED HETEROCYCLIC RING. THE ANTI-FOGGING AGENT MAY BE INCORPORATED IN SILVER HALIDE EMULSION LAYERS OR IN ANOTHER LAYER ADJACENT TO THE EMULSION LAYER TO REDUCE FOG IN THE EMULSION LAYER WITHOUT A SACRIFICE IN THE SENSITIVITY OF THE PHOTOSENSITIVE MATERIALS.

United States Patent Office 3,813,250 SILVER HALIDE PHOTOSENSITIVEELEMENT CONTAINING AN ANTIFOGGING COMBINA- TION OF A NITRATEDHETEROCYCLIC COM- POUND AND A POLYMERIC STABILIZER Yoshihiko Takamura,Yosuke Nakajima, Reiichi Ohi, and Takushi Miyazako, Kanagawa, Japan,assignors to Fuji ghoto Film Co., Ltd., Minami Ashigara-shi, Kanagawa,

apan No Drawing. Filed Oct. 10, 1972, Ser. No. 296,492 Claims priority,applicatign; J9apan, Oct. 11, 1971,

7 Int. Cl. G03c 1/34 US. C]. 96-76 R 15 Claims ABSTRACT OF THEDISCLOSURE Anti-fogging agents for silver halide photographic emulsionsconsisting of a combination of (a) an nitrated benzimidazole, indazoleor benzotriazole compound represented by the general formula it (I)where X and Y individually represent N or CR, wherein R represents ahydrogen atom or alkyl group containing 1 to 4 carbon atoms, and (b) atleast one member selected from polymers containing greater than 50 molpercent of recurring units represented by the general formula BACKGROUNDOF THE INVENTION Field of the invention This invention relates to silverhalide photosensitive materials, in particular, to silver halidephotosensitive materials improved in sensitivity and fog.

Description of the prior art A variety of anti-fogging compounds havebeen incorporated into silver halide photographic emulsions to reducefog. However, the minimization of fog in this way is usually accompaniedby a noticable lowering of sensitivity. To say, it is diflicult tosufiiciently reduce fog without a sacrifice in sensitivity.

3,813,250 Patented May 28, 1974 Summary of the invention We have nowdiscovered that it is possible to remarkably reduce fog with a minimumreduction in sensitivity by incorporating into photographic emulsions acombination of (a) a compound represented by general formula (I) it (I)wherein X and Y individually represent N or CR wherein R represents ahydrogen atom or an alkyl group containing 1 to 4 carbon atoms; and (b)at least one member selected from polymers containing greater than 50mol percent of the recurring unit represented by the general formula\CHI CH/ NRr wherein R and R individually represent a hydrogen atom oran alkyl group containing 1 to 4 carbon atoms or form, when takentogether with the nitrogen and carbon atoms to which they are attached,a 5- to 7-membered heterocyclic ring such as, for example, pyrrolidone,piperidone and caprolactam.

The polymers within the scope of the general formula (II) includehomopolymers composed of the recurring unit represented by the formula(II); copolymers composed of two or more difierent recurring unitsrepresented by the formula (II); and copolymers composed of greater than50 mol percent of at least one recurring unit represented by the formula(II) and at least one monomer which is copolymerizable with the aboverecurring unit.

Examples of the monomer which is copolymerizable with the recurring unitof the formula (II) include the recurring unit represented by generalformula (III) wherein R represents a hydrogen atom or a methyl group,and Z represents OR wherein R is a hydrogen atom or an alkyl grouphaving 1 to 4 carbon atoms; OCOR wherein R is an alkyl group having 1 to4 carbon atoms; OOOR wherein R represents a hydrogen atom or an alkylgroup having 1 to 4 carbon atoms which may be substituted with a hydroxyor an alkyl group having 1 to 4 carbon atoms;

/R1 --0 ON 3 nitrogen atom to which they are attached, a heterocyclicring such as morpholino;

R10 COOR9N/ --COOCH CH N(CH and the like.

Other recurring units which are copolymerizable with the above recurringunit of the formula (II) include maleic anhydride, maleic acid, ahalf-ester of maleic acid, a half-amide of maleic acid and the like.

The preferred polymers are those containing vinylpyrrolidone as therecurring unit of the formula (II).

DETAILED DESCRIPTION OF THE INVENTION The compound represented bygeneral formula I is exemplified by the following compounds.

I-1 S-Nitrobenztriazole N O 3N L2 S-Nitroindazole OzN I-36-Nitroindazole N aN I-4 S-Nitrobenzimidazole nitrate N OzN CH-HNO I-54-Nitrobenzimidazole 4 L6 2Ethyl-S-nitrobenzimidazole These compoundsmay be synthesized by known processes as disclosed in the literature.

Homopolymers having recurring units represented by general formula IIare exemplified by the following compounds.

II-l Poly-N-vinyl-N-methylformamide II-2 Poly-N-vinyl-N-methylacetamide11-3 Poly-N-vinyl-N-methylpropionamide II-4Poly-N-vinyl-N-ethylformamide II-S Poly-N-vinyl-N-ethylacetamide II-6Poly-N-vinyl-N-ethylpropionamide II-7 Poly-N-vinylpyrrolidone II-8Poly-N-vinylpiperidone II-9 Poly-N-vinylcaprolactam Compounds II havingrecurring units represented by general formula III are exemplified bythe following compounds.

III-l Copolymers of N-vinylpyrrolidone with vinyl alcohol III-2Copolymers of N-vinylpyrrolidone with N-methylol acrylamide III-3Copolymers of N-vinylpyrrolidone with N-methylacrylamide III-4Copolymers of N-vinylpyrrolidone with acrylonitrile III-5 Copolymers ofN vinyl-N-methylformamide vinyl alcohol III-6 Copolymers ofN-vinyl-N-methylformamide acrylic acid III-7 Copolymers ofN-vinyl-N-methylformamide vinyl acetate III-8 Copolymers ofN-vinylN-methylformamide acryloylmorpholine with with

with

with

III-9 Copolymers of N-vinyl-N-ethylformamide with vinyl alcohol III-10Copolymers of N-vinyl-N-ethylformamicle with acrylamide III-11Copolymers of N-vinyl-N-ethylformamide with acrylonitrile III-12Copolymers of N-vinyl-N-ethylformamide with methacrylic acid While thereis no special restriction on the molecular weight of the abovehomopolymers and copolymers, those preferably used have molecularweights within the range from about 4,000 to about 1,000,000, moredesirably from 5,000 to 500,000 and having inherent viscosities withinthe range of from about 0.1 to about 3.0, more desirably 0.2 to 1.0, asdetermined in water at a temperature of 30 C. Homopolymers andcopolymers having a molecular weight excessively lower than the aboverange tend to give poor results and, the other hand, those having amolecular weight excessively higher than the above range cannot easilybe handled because of their high viscosity in the gelatin solution.

Compound I preferably is incorporated in an amount of from about 0.5 toabout 250 mg., more desirably from 0.5 to mg., per mole of silver halidecontained in a silver halide emulsion, and compound II is incorporatedin an amount of from about 0.05 to about 15 g., preferably from 0.05 tog., per mole of silver halide.

It is preferred to incorporate aforesaid compounds I and H in anemulsion during the period from the second ageing to just beforeapplication of the emulsion to a support. As earlier indicated, aportion or the total amount of the compounds may be incorporated in alayer adjacent the emulsion layer. In such a case, the total amounts ofeach of the compounds I and II in both layers can be the same amounts asthose described for the com pounds I and II contained in only theemulsion layer, i.e., the total amounts of each of the compounds I andII in the emulsion layer and a layer adjacent to the emulsion layer canrange from about 0.5 to about 250 mg., preferably from 0.5 to 100 mg.,per mole of silver halide contained in the silver halide emulsion layerand from about 0.05 to about 15 g., preferably from 0.05 to 5 g., permole of the silver halide contained in the silver halide emulsion layer,respectively.

The present invention is applicable to any silver halide emulsion, suchas silver iodide emulsions, silver chlorobromide emulsions and silverchloroiodobromide emulsions. The emulsions may be sulfur-sensitized,gold-sensitized or reductively sensitized or may have incorporatedtherein spectral sensitizers, polyalkylene oxide-type sensitizers,various stabilizers, hardeners, coating assistants, couplers or likeconventional adjuvants.

Any conventional support for photosensitive materials may be used inaccordance with the present invention, e.g., glass, cellulose acetatefilms, poly(ethylene terephthalate) films, polycarbonate films,polystyrene films, polypropylene film, baryta paper and likeconventional sheet materials which have been used as supports for silverhalide photo-emulsions.

According to the present invention, the fog in the silver halidephotosensitive materials is minimized with a minimum decrease insensitivity.

Some embodiments of the present invention are illustrated by thefollowing examples which are not to be taken as limitative of theinvention.

EXAMPLE 1 A high sensitivity X-ray gelatin-silver iodobromide emulsioncontaining 1.5 mol percent of silver iodide (based on silver bromide)which was sulfur-sensitized by sodium thiosulfate and gold-sensitized bygold chloride containing 4-hydroxy-6-methyl-l,3,3a,7-tetrazoindene in anamount of 0.5 g./mol AgX, saponin in an amount of 0.5 g./mol AgX andmucochloric acid in an amount of 0.15 g./mol AgX was divided into 23portions. To each portion was then added compounds I and II alone or incombinations of compounds I and II, in amounts as indicated in Table 1,to form an emulsion. The emulsion was applied to a poly(ethyleneterephthalate) base and dried to provide a photosensitive material.

Each of the specimens thus obtained was exposed for & second through ablue'filter to a light source of a trol material and the addition ofcompound II alone has little effect on sensitivity. However, theaddition of compound I in combination with compound II reduces fog withonly a slight decrease in sensitivity.

TABLE 1 Compound I Compound II Amount Amount Relative Specimen added(mg./ added (g.! sensi- No. No. mol AgX) No. mol AgX) tlvity l FogControl. 100 0. 12 A- 11-7 1.35 105 0. 13 B- I-l. 22 75 0.07 C 55 35 0.02 D I 55 11-7 0. 27 55 0. 02 E. 55 11-7 1. 35 75 0. 03 F.. 55 11-7 2.70 95 0. 05 G- II-9 1.35 105 0.13 H- 55 11-9 0. 27 50 0. 02 I 55 IL!) 1.35 0. 02 I 55 11-9 2. 70 0. 03 K- 55 11-9 5. 40 90 0. 05 III-1 l. 35 1000. 12 M. 0.27 45 0. 02 N- 1. 35 55 0.02 0 I-1 4. 05 0. 04 P I-l 6. 75 950. 07 A. 1. 35 105 0. 13 Q I 0.08 R. 40 0. 03 8.; 7 50 0. 03 T 1. 35 650. 04 U I-3 2. 70 80 0. 05 V L3 4. 05 0. 07

Relative sensitivity stands for a relative value of sensitivity at thedensity of fog +0.3 referring to as the control value.

NOTES:

11-7: [7; =0.15 (corresponding to a molecular weight of 10,000). 11-9:[1 =0.37 (corresponding to a molecular weight of 50,000). III-1: 1]=0.28 (corresponding to a molecular weight of 30,000)

a 7:3 eopolymer of N-vinylpyrrolidone with vinyl alcohol.

EXAMPLE 2 The same high sensitivity X-ray gelatin-silver iodobromideemulsion as was used in Example 1 was, after the addition of astabilizer, a wetting agent and a hardener as in Example 1, divided into5 portions, Compound II-7 was added to certain portions, or not added,in the amounts as indicated in Table 2.

On the other hand, a 7% aqueous gelatin emulsion had added theretosaponin in an amount of 5 g./liter and mucochloric acid in an amount of0.4 g./liter and was divided into 5 portions, and certain portions hadadded thereto compound I-1 in the amount indicated in Table 2. Each ofthe resulting solutions was applied as an adjacent layer over a layer ofone of the above emulsions and dried to obtain 5 specimens. Thespecimens were exposed and developed under the same conditions as inExample 1 and subjected to sensitivity and fog determinations. Theresults obtained are summerized in Table 2.

Table 2. shows that it is possible to obtain a result similar to Example1 by incorporating one component of the anti-fogging agent of thepresent invention into an emulsion layer and the other into an adjacentlayer.

NOTE: 11-7: 11 ]=0.87 (corresponding to a molecular weight of 30,000).

color temperature of 5,400 K. and then developed at 70 35 C. for 25seconds in a high pH l-phenyl-S-pyrazolidone-hydroquinone type solutionfor X-ray films. The results are summarized in Table 1.

Table 1 shows that the addition of compound I alone EXAMPLE 3 Asulfurand gold-sensitized color silver iodobromide emulsion containingsilver iodide in an amount of 5 mol percent had added thereto4-hydroxy-6-methy1-1,3,3a,7- tetrazoindene in an amount of 0.7 g./molAgX, an alkylremarkably reduces senstivity as compared with the con- 75benzenesulfonate in an amount of 0.8 g./mol AgX, mu-

chloric acid in an amount of 0.3 g./mol AgX and a coupler compoundhaving the following structure in an amount of 50 mg./mol AgX:

O ONHCnHn i S OzNB The emulsion was then divided into 8 portions, and toeach portion was added compound I or II alone or as a combination ofcompounds I and II in accordance with the present invention. Theportions were then applied to a cellulose acetate film base and dried toprovide a photosensitive film.

The film was exposed and developed in a color developing solutioncontaining 4-amino-3-methyl-N,N-diethylaniline. The results aresummerized in Table 3. Table 3 shows that the anti-fogging agent of thepresent invention reduces fog with only a slight decrease in sensitivityin color photographic emulsions.

TABLE 3 NOTE; 11-7: [1 ]=0.25 (corresponding to a molecular weight of30,000).

EXAMPLE 4 The same high sensitivity X-ray gelatin-silver iodobromideemulsion as was used in Example 1 had added thereto a stabilizer, awetting agent and a hardener as in Example 1, and was divided into 5portions. To each portion was added an anti-fogging compound, as listedin Table 4, and the portions then applied to a poly(ethyleneterephthalate) base and dried to provide specimens. The specimens wereexposed and developed under the same conditions as in Example 1 andsubjected to relative sensitivity and fog determinations. The resultsthus obtained are summerized in Table 4. As indicated by Table 4, therewere obtained silver halide photosensitive materials with a highrelative sensitivity and a reduced fog, as in Example 1.

II-i': ]=0.15 (corresponding to a molecular weight of 10,000). III-1:11]=0.28 (corresponding to a molecular weight of 30,000) a 7:3 copolymerof N-vinylpyrrolidone with vinyl alcohol.

While the invention has been described in detail and with reference tospecific embodiments thereof, it will be apparent to one skilled in theart that various changes and modification can be made therein withoutdeparting 75 from the spirit and scope thereof.

N/ t m where X and Y individually represent N or CR wherein R representsa hydrogen atom or alkyl group containing 1 to 4 carbon atoms; and (b)at least one member selected from polymers containing greater than 50mol percent of the recurring unit represented by the general formula il. \C 2 CH N-R, 0:33-34 (11) wherein R and R individually represent ahydrogen atom or an alkyl group containing 1 to 4 carbon atoms or form,when taken together with the nitrogen and carbon atoms to which they areattached, a 5- to 7-membered heterocyclic ring selected from the groupconsisting of pyrrolidone, piperidone and caprolactam, said polymersbeing homopolymers composed of the recurring unit represented by theformula (II); copolymers composed of two or more different recurringunits represented by the formula (II); and copolymers composed ofgreater than 50 mol percent of at least one recurring unit representedby the formula (II) and at least one monomer which is copolymerizablewith the above recurring unit, said monomer having the general formula(III) Z (III) wherein R represents a hydrogen atom or methyl group, andZ represents -OR wherein R is a hydrogen atom or an alkyl group having 1to 4 carbon atoms; OCOR wherein R is an alkyl group having 1 to 4 carbonatoms; -COOR wherein R represents a hydrogen atom or an alkyl grouphaving 1 to 4 carbon atoms which may be substituted with hydroxy or analkyl group having 1 to 4 carbon atoms;

R1 CON wherein R and R each represents a hydrogen atom or an alkyl grouphaving 1 to 4 carbon atoms which may be substituted with hydroxy or analkyl group having 1 to 4 carbon atoms, or form, when taken togetherwith the nitrogen atom to which they are attached,

a morpholino ring;

/R1o -COORoN wherein R represents an alkylene chain having 2 to 3 carbonatoms and R and R each represents a hydrogen atom or an alkyl grouphaving 1 to 4 carbon atoms; CN; phenyl or sulfophenyl; or a pyridylring, the compound of general formula (I) being contained in an amountof from about 0.5 to about 250 mg. per mole of silver halide and thepolymer containing greater than 50 mole percent of the recurring unitrepresented by the general formula (II) being contained in an amountfrom about 0.05 to about 15 g. per mole of silver halide.

2. The silver halide photosensitive material as in claim 1 which furthercomprises a layer adjacent to said silver halide emulsion layer.

3. The silver halide photosensitive material as in claim 1 in which thecopolymer having recurring units represented by general formula II ispresent and is contained in an amount of about 0.05 to about 15 g. permol of silver halide.

4. The silver halide photosensitive material as in claim 1 whichcontains a compound represented by general formula I and a homopolymerhaving recurring units represented by general formula II.

5. The silver halide photosensitive material as in claim 1 whichcontains a compound represented by general formula I and a copolymerhaving recurring units represented by general formula II.

6. The silver halide photosensitive material as in claim 2 in which oneof the constituent (a) and (b) is contained in the emulsion layer andthe other is contained in the adjacent layer.

7. The silver halide photosensitive material as in claim 1 in which bothconstituents (a) and (b) are contained in the emulsion layer.

8. The silver halide photosensitive material as in claim 2 in which bothconstituents (a) and (b) are contained in the adjacent layer.

9. The silver halide photosensitive material as in claim 1 in which thehomopolymer having recurring units represented by general formula II ispresent and is contained in an amount of about 0.05 to about 15 g. permol of silver halide.

10. The silver halide photosensitive material as in claim 1 in which thecompound represented bygeneral formula (I) is selected from the groupconsisting of S-nitrobenztriazole, S-nitroindazole, fi-nitroindazole,-nitrobenzimidazole nitrate, 4-nitrobenzimidazole and 2-ethyl-S-nitrobenzimidazole.

11. The silver halide photosensitive material as in claim 1 wherein saidpolymer containing greater than 50 mole percent of the recurring unitrepresented by the general formula (II) is a homopolymer selected fromthe group consisting of poly-N-vinyl-N-methylformamide, poly-N-vinyl-N-methylacetamide, poly-N-vinyl-N-methylpropionamide,poly-N-vinyl-N-ethylformamide, poIy-N-vinyl-N- ethylacetamide,poly-N-vinyl-N-ethylpropionamide, poly- N-vinylpyrrolidone,poly-N-vinylpiperidone and poly-N- vinylcaprolactam.

12. The silver halide photosensitive material as in claim 1 in which thepolymer containing greater man mole percent of the recurring unitrepresented by the general formula (III) is selected from the groupconsisting of copolymers of N-vinylpyrrolidone with vinyl alcohol, N-vinylpyrrolidone with N-methylol acrylarnide, N-vinylpyrrolidone withN-methylacrylamide, N-vinylpyrrolidone with acrylonitrile,N-vinyl-N-methylformamide with vinyl alcohol, N-vinyl-N-methylformamidewith acrylic acid, N-vinyl-N-rnethylformamide with vinyl acetate,N-vinyl- N-methylformamide with acryloylmorpholine, N-vinyl-N-ethylformamide with vinyl alcohol, N-vinyl-N-ethylformamide withacrylamide, N-vinyl-N-ethylformamide with acrylonitrile andN-vinyl-N-ethylformamide with methacrylic acid.

13. The silver halide photosensitive material as in claim 1 in which anyhomopolymer or copolymer has a molecular weight of from about 4,000 toabout 1,000,000.

14. The silver halide photosensitive material as in claim 13 where themolecular weight is from 5,000 to 500,000.

15. The silver halide photosensitive material as in claim 1 where thetotal amount of the compound of general formula (I) is from 0.5 to mg.per mole of silver halide contained in the silver halide emulsion layerand the total amount of the polymer containing greater than 50 molepercent of the recurring unit represened by the general formula (II) isfrom 0.05 to 5 g. per mole of the silver halide contained in the silverhalide emulsion layer.

References Cited UNITED STATES PATENTS 3,505,067 4/1970 Dersch et al.96-109 3,671,255 6/1972 Haga et al. 96-109 RONALD H. SMITH, PrimaryExaminer W. H. LOUIE, JR., Assistant Examiner US. Cl. X.R. 96-109

